Glass roll and method of processing glass roll

ABSTRACT

A roll-to-roll apparatus reliably reduces breakage of a glass film even in a case of sequentially performing predetermined processing on the glass film. Provided is a glass roll ( 1 ) formed by winding a glass film ( 2 ) into a roll, in which a resin film ( 4 ) is attached onto the glass film ( 2 ), and at least a part of the resin film ( 4 ) is arranged on a front side of an unwinding direction relative to a leading end portion in the unwinding direction of the glass film ( 2 ).

TECHNICAL FIELD

The present invention relates to a package form for a glass film whichis used as a glass substrate for a flat panel display and a solar cell,and used as cover glass or the like for an organic light-emitting diode(OLED) lighting, and to a processing method for the glass film.

BACKGROUND ART

As is well known in the art, in recent years, there is a demand forfurther thinning of various glass plates including glass substrates fora flat panel display, such as a liquid crystal display, a plasmadisplay, an organic light-emitting diode (OLED) display, or a fieldemission display. Therefore, along with the demand, a so-called glassfilm that is thinned into a film is being developed. For example, asdisclosed in Patent Literature 1, a glass film having a thickness of 200μm or less has been developed.

Further, for example, as disclosed in Patent Literature 2, as a packageform for the glass film, there is adopted a glass roll formed by windingthe glass film into a roll. The package form utilizes a characteristicthat the glass film has sufficient flexibility due to its thinness, andhas an advantage that it is possible to save a space occupied by thepackaged glass film.

In addition, for example, as disclosed in Patent Literature 3, the glassroll is supplied while being unwound, a functional film is formed on asurface of the glass film, and then the glass film having the surface onwhich the functional film is formed is wound again. Thus, the functionalfilm is formed on the glass film using a so-called roll-to-roll method.In this way, only by unwinding the glass film from the glass rollsuccessively, film forming processing can be performed on the glass filmsequentially, which is convenient.

Citation List Patent Literature

Patent Literature 1: JP 2008-133174 A

Patent Literature 2: JP 2002-544104 A

Patent Literature 3: JP 2007-119322 A

SUMMARY OF INVENTION Technical Problem

By the way, as disclosed in Patent Literature 3, an apparatus forcarrying out the roll-to-roll method (hereinafter, referred to asroll-to-roll apparatus) includes an unwinding section and a windingsection, and performs predetermined processing such as the film formingon the glass film between the unwinding section and the winding sectionwhile successively supplying the glass film from the unwinding sectionto the winding section. Therefore, in a case where the roll-to-rollapparatus performs the predetermined processing on the glass film,first, it is necessary to guide, into the winding section, the glassfilm that is unwound from the glass roll set in the unwinding section,and to set the glass film between the unwinding section and the windingsection.

However, when guiding the glass film first from the unwinding section tothe winding section, a posture of a leading end portion of the glassfilm is liable to be unstable. Thus, the leading end portion of theglass film is excessively and repeatedly brought into contactwith/impact on apparatus components, which may sometimes lead to such asituation that small flaws are formed in a vicinity of the leading endportion. This situation may cause a problem in that the vicinity of theleading end portion of the glass film breaks due to the small flaws.

Further, when the vicinity of the leading end portion of the glass filmbreaks, the glass film is cut halfway through the processing due to thebreakage in some cases. In this case, intended tension does not act onthe glass film in the roll-to-roll apparatus, and hence a bend and aflutter occur also in an intermediate portion or the like in alongitudinal direction of the glass film. As a result, a portion of theglass film other than the leading end portion thereof is also broughtinto unnecessary contact with the apparatus components, which may leadto a major problem such as escalation of breakage of the glass film.

In view of the above-mentioned circumstances, it is a technical objectof the present invention to reliably reduce breakage of the glass filmeven when performing the predetermined processing on the glass film bythe roll-to-roll apparatus.

Solution to Problems

The present invention, which has been made to solve the above-mentionedproblems, provides a glass roll, which is formed by winding a glass filminto a roll, in which a resin film is attached onto the glass film, andat least a part of the resin film is arranged on a front side of anunwinding direction relative to a leading end portion in the unwindingdirection of the glass film.

With this configuration, when guiding the glass film first from anunwinding section to a winding section of a roll-to-roll apparatus, itis possible to perform the guiding operation while the resin film havinghigher fracture toughness in comparison with the glass film is in thelead. Further, the glass film is guided into the roll-to-roll apparatusafter the resin film by being dragged by the resin film, and hence theglass film is less likely to be excessively brought into contactwith/impact on apparatus components. Therefore, it is possible toreliably reduce such a situation that the glass film breaks at the timeof the guiding operation.

In the above-mentioned configuration, the resin film may be coupled tothe leading end portion in the unwinding direction of the glass film.

With this configuration, it is possible to easily and reliably positionthe resin film on the front side of the unwinding direction relative tothe leading end portion in the unwinding direction of the glass film.

In this case, it is preferred that the resin film be coupled also to atrailing end portion in the unwinding direction of the glass film, andat least a part of the resin film be arranged on a rear side of theunwinding direction relative to the trailing end portion in theunwinding direction of the glass film.

The roll-to-roll apparatus needs to keep constant tension between theunwinding section and the winding section. When the resin film iscoupled to the trailing end portion in the unwinding direction of theglass film, the constant tension can act on the glass film through theresin film even after the trailing end portion of the glass film is sentout of the unwinding section. Therefore, even after the trailing endportion of the glass film is sent out of the unwinding section, it ispossible to stably perform predetermined processing on the glass film,which may contribute to effective use of the glass film.

Further, in a case where a plurality of roll-to-roll apparatus performthe processing, it is possible to obtain the following action andeffect. That is, in this case, a portion that is treated as the trailingend portion in the processing of the previous roll-to-roll apparatus iswound last, and hence is treated as the leading end portion in theprocessing of the subsequent roll-to-roll apparatus. Therefore, whencoupling the resin films respectively to the leading end portion and thetrailing end portion of the glass film in this way, without rewindingthe glass roll for every roll-to-roll apparatus so that a side on whichthe resin film is coupled serves as the leading end portion, the side onwhich the resin film is coupled can be always treated as the leading endportion, and hence efficient processing is possible.

In the above-mentioned configuration, it is preferred that the glassfilm and the resin film be coupled to each other with an elastic member.

When the glass film and the resin film are coupled to each other, in acase where the glass film and the resin film are supplied to theroll-to-roll apparatus under a state in which a widthwise center line ofthe glass film and a widthwise center line of the resin film are notpresent on the same straight line, the following problem may arise. Thatis, when displacement occurs between the widthwise center lines of theresin film and the glass film, the roll-to-roll apparatus forciblycorrects displacement of the glass film, and hence bending stress andtorsional stress act on the portion of the glass film coupled to theresin film. Consequently, the glass film may break.

In view of this, in order to prevent the breakage, it is preferred thatthe glass film and the resin film be coupled to each other with theelastic member as described above. With this configuration, even if thewidthwise center line of the glass film and the widthwise center line ofthe resin film are not present on the same straight line, the elasticmember is deformed at the point in time when the tension acts on theglass film, to thereby absorb the displacement between the widthwisecenter line of the glass film and the widthwise center line of the resinfilm. Therefore, owing to the displacement absorbing effect exerted bythe elastic member, the bending stress and torsional stress are lesslikely to be generated on the glass film, and hence it is possible toprevent breakage of the glass film. Note that, in a case where the resinfilm is coupled also to the trailing end portion in the unwindingdirection of the glass film, it is preferred that the glass film and theresin film be coupled to each other with the elastic member at both ofthe leading end portion and the trailing end portion in the unwindingdirection of the glass film.

In this case, it is preferred that the elastic member couple a regionincluding a widthwise center line of the glass film and a widthwisecenter line of the resin film.

With this configuration, the elastic member couples the region includingthe widthwise center line of the glass film to the region including thewidthwise center line of the resin film, and hence, even when an area ofthe portion coupled with the elastic member is reduced, it is possibleto couple the films to each other in stable postures. Accordingly, owingto a reduction in area of the portion coupled with the elastic member,the stress can be reduced as much as possible, which acts on the glassfilm when the elastic member is deformed to absorb the displacementbetween the widthwise center line of the glass film and the widthwisecenter line of the resin film. Therefore, this is effective also in viewof preventing breakage of the glass film.

In the above-mentioned configuration, it is preferred that the glassfilm and the resin film be coupled to each other under a state in whichan end portion of the resin film is superposed on an end portion of theglass film.

With this configuration, an end surface of the glass film and an endsurface of the resin film are out of direct contact with each other, andhence this is advantageous in view of preventing breakage of the glassfilm.

In the above-mentioned configuration, the resin film longer in lengththan the glass film may be superposed and attached onto one surface ofthe glass film, and the resin film may be extended beyond the leadingend portion in the unwinding direction of the glass film.

With this configuration, while protecting the one surface of the glassfilm with the resin film, the roll-to-roll apparatus can perform thepredetermined processing on another surface of the glass film.

In this case, it is preferred that the resin film be extended alsobeyond a trailing end portion side in the unwinding direction of theglass film.

With this configuration, the same resin film is extended beyond both thefront and rear sides of the unwinding direction of the glass film. Thus,even after the trailing end portion of the glass film is sent out of theunwinding section of the roll-to-roll apparatus, the constant tensioncan act on the glass film through the resin film. Therefore, even afterthe trailing end portion of the glass film is sent out of the unwindingsection, it is possible to stably perform the predetermined processing,and hence it is possible to achieve effective use of the glass film.

Further, in the case where the plurality of roll-to-roll apparatusperform the processing, it is possible to obtain the following actionand effect. That is, in this case, the portion that is treated as thetrailing end portion in the processing of the previous roll-to-rollapparatus is wound last, and hence is treated as the leading end portionin the processing of the subsequent roll-to-roll apparatus. Therefore,when the resin film is extended beyond each of the leading end portionand the trailing end portion of the glass film in this way, withoutrewinding the glass roll for every roll-to-roll apparatus so that a sidebeyond which the resin film is extended serves as the leading endportion, the side beyond which the resin film is extended can be alwaystreated as the leading end portion, and hence efficient processing ispossible.

In the above-mentioned configuration, the glass film may include aplurality of glass films, and the plurality of glass films may beattached onto the same resin film.

With this configuration, the plurality of glass films with shortlengths, which are previously cut into fixed lengths at user's request,etc., can be supplied to the roll-to-roll apparatus. Further, even theplurality of glass films with short lengths, which are cut due to adefect and the like at a stage of not having predetermined lengths, canbe packaged in a state of the glass roll. As a result, the predeterminedprocessing can be performed not only on the glass film with a longlength but also on the glass film with a short length using theroll-to-roll apparatus.

In the above-mentioned configuration, the resin film may be superposedand attached onto the one surface of the glass film, and an anotherresin film separate from the resin film may be superposed and attachedonto another surface of the glass film.

With this configuration, front and back surfaces of the glass film areprotected with the resin films. Further, just before performing thepredetermined processing by the roll-to-roll apparatus, by peeling offthe resin film attached on a surface that is to be subjected to theprocessing, it is possible to carry out the processing without anyproblem.

The present invention, which has been made to solve the above-mentionedproblems, provides a processing method for a glass roll, forsequentially performing, by a roll-to-roll apparatus, predeterminedprocessing on a glass roll including a glass film wound into a roll, theprocessing method including: attaching a resin film onto the glass film;arranging at least a part of the resin film on a front side of anunwinding direction relative to a leading end portion in the unwindingdirection of the glass film; and guiding the glass film into theroll-to-roll apparatus while the resin film is in the lead.

According to this method, it is possible to similarly obtain theabove-mentioned action and effect.

In the above-mentioned method, it is preferred that a length of theresin film, which corresponds to a part on the front side of theunwinding direction relative to the leading end portion in the unwindingdirection of the glass film, be equal to or larger than an entire lengthof a conveyance path for the glass film in the roll-to-roll apparatus.

With this configuration, only the resin film is present in an inside ofthe roll-to-roll apparatus at an early stage of operation, and hence itis possible to smoothly perform guiding operation into the inside of theroll-to-roll apparatus without paying any attention to the breakage ofthe glass film.

In the above-mentioned method, it is preferred that at least a part ofthe resin film be arranged also on a rear side of the unwindingdirection relative to a trailing end portion in the unwinding directionof the glass film. Note that, the resin film described herein may beintegrated with or separated from the resin film arranged on the frontside of the unwinding direction relative to the leading end portion inthe unwinding direction of the glass film.

With this configuration, it is possible to similarly obtain theabove-mentioned action and effect.

In this case, it is preferred that a length of the resin film, whichcorresponds to a part on the rear side of the unwinding directionrelative to the trailing end portion in the unwinding direction of theglass film, be equal to or larger than the entire length of theconveyance path for the glass film in the roll-to-roll apparatus.

With this configuration, tension can act on the glass film even at thepoint in time when the predetermined processing is performed on thetrailing end portion in the unwinding direction of the glass film.Therefore, it is possible to perform stable processing over an entirelength of the glass film.

Advantageous Effects of Invention

According to the present invention as described above, when guiding theglass film first from the unwinding section to the winding section ofthe roll-to-roll apparatus, it is possible to perform the guidingoperation while the resin film attached on the glass film is in thelead. Therefore, the leading end portion, which is likely to be broughtinto contact with the apparatus components of the roll-to-rollapparatus, is formed of the resin film. Thus, at the time of the guidingoperation, such a situation can be reduced as much as possible that theglass film is brought into contact with the apparatus components, tothereby break.

BRIEF DESCRIPTION OF DRAWINGS

[FIG. 1] A perspective view illustrating an entire configuration of aglass roll according to a first embodiment of the present invention.

[FIG. 2] A schematic view illustrating a roll-to-roll apparatus used forprocessing the glass roll according to the first embodiment.

[FIG. 3] A plan view illustrating a state in which a glass film of theglass roll according to a second embodiment of the present invention isdeveloped on a straight line.

[FIG. 4( a)] A plan view illustrating a coupled portion between a resinfilm and the glass film of the glass roll according to a thirdembodiment of the present invention, and illustrating a state beforetension acts on the glass film.

[FIG. 4( b)] A plan view illustrating the coupled portion between theresin film and the glass film of the glass roll according to the thirdembodiment of the present invention, and illustrating a state after thetension acts on the glass film.

[FIG. 5( a)] A plan view illustrating a coupled portion between theresin film and the glass film of the glass roll according to a fourthembodiment of the present invention, and illustrating a state beforetension acts on the glass film.

[FIG. 5( b)] A plan view illustrating the coupled portion between theresin film and the glass film of the glass roll according to the fourthembodiment of the present invention, and illustrating a state after thetension acts on the glass film.

[FIG. 6( a)] A plan view illustrating a state in which the glass film ofthe glass roll according to a fifth embodiment of the present inventionis developed on a straight line.

[FIG. 6( b)] A side view of FIG. 6( a).

[FIG. 7] A plan view illustrating a state in which glass films of theglass roll according to a sixth embodiment of the present invention aredeveloped on a straight line.

[FIG. 8( a)] A plan view illustrating a state in which the glass film ofthe glass roll according to a seventh embodiment of the presentinvention is developed on a straight line.

[FIG. 8( b)] A sectional view taken along the line A-A of FIG. 8( a).

[FIG. 9] A schematic view illustrating a roll-to-roll apparatus used forprocessing the glass roll according to the seventh embodiment.

[FIG. 10( a)] A plan view illustrating a state in which the glass filmsof the glass roll according to a modified example of the seventhembodiment of the present invention are developed on a straight line.

[FIG. 10( b)] A sectional view taken along the line B-B of FIG. 10( a).

[FIG. 11] A schematic view illustrating a modified example of theroll-to-roll apparatus used for processing the glass roll according tothe present invention.

[FIG. 12] A schematic view illustrating another modified example of theroll-to-roll apparatus used for processing the glass roll according tothe present invention.

DESCRIPTION OF EMBODIMENTS

In the following, embodiments of the present invention are describedwith reference to the attached drawings.

FIG. 1 is a perspective view illustrating an entire configuration of aglass roll according to a first embodiment of the present invention. Aglass roll 1 is formed by winding a glass film 2 onto an outerperipheral surface of a roll core 3 into a roll. A resin film 4 iscoupled onto a leading end portion in a unwinding direction of the glassfilm 2, and a part of the resin film 4 protrudes from the leading endportion of the glass film 2 to a front side of the unwinding direction.Specifically, in this embodiment, the glass film 2 and the resin film 4are coupled to each other in such a manner that adhesive tapes 5 areattached across the glass film 2 and the resin film 4 under a state inwhich an end portion of the glass film 2 and an end portion of the resinfilm 4 are superposed on each other.

The glass film 2 is formed by an overflow downdraw method to have athickness of from 1 μm to 200 μm (preferably, 10 μm to 100 μm). Thereason why the glass film is set to have such a thickness is because,with the thickness within the above-mentioned numerical range,appropriate flexibility and strength can be imparted to the glass film 2and no trouble arises at the time of winding. In other words, when thethickness of the glass film 2 is less than 1 μm, handling of the glassfilm is troublesome because of lack of strength. When the thickness ofthe glass film 2 exceeds 200 μm, satisfactory flexibility is notobtained, which leads to a problem in that a winding radius is extremelyand inevitably increased.

In this embodiment, a width of the glass film 2 is 12.5 mm or more, inparticular, preferably 100 mm or more, more preferably 300 mm or more,and still more preferably 500 mm or more. Note that, the glass film 2 isused for a wide variety of devices including a small-screen display suchas a mobile phone with a small size and a large-screen display such as atelevision set with a large size, and hence it is preferred that thewidth of the glass film 2 be finally selected as needed depending on asize of a substrate of a device to be used.

As a glass composition of the glass film 2, there can be used variousglass compositions of silicate glass and the like, such as silica glassand borosilicate glass. However, it is preferred to use non-alkaliglass. The reason is as follows. When the glass film 2 contains analkali component, a phenomenon, so-called white weathering, occurs sothat the glass film is structurally rough. When the glass film 2 iscurved, there is a risk in that the glass film is prone to break from aportion that is weathered over time. Note that, herein, the non-alkaliglass includes glass that does not substantially contain an alkalicomponent, specifically, glass containing an alkali metal oxide of 1000ppm or less (preferably, of 500 ppm or less, and more preferably, of 300ppm or less).

Further, in view of ensuring strength of the glass film 2, it ispreferred that at least each end surface in a width direction of theglass film 2 include a cut surface which is cut by laser splitting. Withthis configuration, the each end surface in the width direction of theglass film 2 has a cross-section with high strength free from defectscausing breakage, such as micro cracks. Specifically, when utilizing thelaser splitting, without being subjected to polishing or the like afterthe cutting, the each end surface in the width direction of the glassfilm 2 is allowed to have an arithmetic average roughness Ra (compliantto JIS B0601:2001) of 0.1 μm or less (preferably, 0.05 μm or less).Here, the laser splitting refers to a method of cutting the glass film 2in such a manner that an initial crack is caused to develop by utilizingthermal stress that is generated through expansion due to a heatingaction of laser and through contraction due to a cooling action of arefrigerant.

A thickness and a width of the resin film 4 are not particularlylimited. However, considering that the resin film is caused to passthrough in the same roll-to-roll apparatus as the glass film 2, it ispreferred that the resin film have substantially the same thickness andwidth as those of the glass film 2. Specifically, it is preferred thatthe thickness of the resin film 4 be from 1 to 200 μm, and the width ofthe resin film 4 be 0.5 to 2 times (preferably 0.9 to 1.5 times) largerthan the width of the glass film 2. Note that, the resin film 4 needs tohave strength high enough to drag the glass film 2, and hence it ispreferred to finally determine the thickness and the width inconsideration of a material and the like of the resin film 4.

As the resin film 4, there can be used, for example, an ionomer film, apolyethylene film, a polypropylene film, a polyvinyl chloride film, apolyvinylidene chloride film, a polyvinyl alcohol film, a polyesterfilm, a polycarbonate film, a polystyrene film, a polyacrylonitrilefilm, an ethylene vinyl acetate copolymer film, an ethylene-vinylalcohol copolymer film, an ethylene-methacrylate copolymer film, a nylon(registered trademark) film (polyamide film), a polyimide film, and anorganic resin film (synthetic resin film) such as cellophane. Inaddition, in view of ensuring both cushioning performance and strength,it is preferred that, as the resin film 4, a foamed resin sheet such asa polyethylene foam sheet be used.

Next, the roll-to-roll apparatus for performing predetermined processingon the glass roll 1 configured as described above, and the procedure forprocessing the glass film 2 by the apparatus are briefly described.

FIG. 2 is a schematic view illustrating an example of the roll-to-rollapparatus. The roll-to-roll apparatus includes an unwinding section 11arranged at an upstream end of a conveyance path, and a winding section12 arranged at a downstream end of the conveyance path. Between theunwinding section 11 and the winding section 12, the predeterminedprocessing is performed on the glass film 2.

Specifically, after the glass roll 1 is set in the unwinding section 11,the predetermined processing is performed successively while conveyingrollers 13 a to 13 n sequentially convey, to a downstream side, theglass film 2 which is unwound from the glass roll 1 set in the unwindingsection 11, and then the glass film 2 subjected to the predeterminedprocessing is sequentially wound in the winding section 12. In this way,the glass roll 1 is produced again.

In this embodiment, on the conveyance path between the unwinding section11 and the winding section 12, in order from an upstream side of theconveyance path, there are arranged a cleaning chamber 14 which poolscleaning liquid (for example, water), a drying chamber 15 in which theglass film 2 dipped into the cleaning liquid of the cleaning chamber 14is dried with hot air or the like, and a static elimination chamber 16in which static electricity accumulated on the glass film 2 iseliminated. In order from the upstream side, a cleaning process, adrying process, and a static elimination process are performed on theglass film 2. Note that, in FIG. 2, reference numeral 17 denotes adraining section, and reference numeral 18 denotes a surface treatmentsection.

Further, as described above, in order for the roll-to-roll apparatus toperform the predetermined processing such as cleaning on the glass film2, first, it is necessary to guide the glass film 2 unwound from theglass roll 1 set in the unwinding section 11 into the winding section12, and to stretch the glass film 2 between the unwinding section 11 andthe winding section 12. At this time, when the glass film 2 is guidedinto an inside of the roll-to-roll apparatus while the leading endportion in the unwinding direction of the glass film 2 is in the lead,the leading end portion of the glass film 2 is excessively andrepeatedly brought into contact with/impact on apparatus components ofthe roll-to-roll apparatus, and hence the glass film 2 may break. Inview of this, as illustrated in FIG. 1, the resin film 4 is coupled onthe leading end portion of the glass film 2, and the glass film 2 isguided into the inside of the roll-to-roll apparatus while the resinfilm 4 is in the lead.

That is, the resin film 4 has higher fracture toughness in comparisonwith the glass film 2. Thus, even when the resin film is brought intocontact with the apparatus components to have small flaws, the resinfilm does not break due to the small flaws. Therefore, when the glassfilm 2 is guided into the inside of the roll-to-roll apparatus while theresin film 4 is in the lead, it is possible to reliably reduce such asituation that the glass film 2 is flawed due to excessive contact withthe apparatus components.

Here, in view of preventing breakage of the glass film 2, it ispreferred that a length of the resin film 4 (indicated by D1 of FIG. 3described below), which corresponds to a part on the front side of theunwinding direction relative to the leading end portion in the unwindingdirection of the glass film, be equal to or larger than an entire lengthof the conveyance path provided in the inside of the roll-to-rollapparatus. With this configuration, only the resin film 4 is present inthe inside of the roll-to-roll apparatus at an early stage of operation,and hence it is possible to smoothly perform guiding operation from theunwinding section 11 to the winding section 12 without paying anyattention to the breakage of the glass film 2.

Note that, in the above-mentioned embodiment, description is made of thecase where the glass film 2 is wound around the roll core 3 into a roll,to thereby manufacture the glass roll 1. However, in view of protectinga surface of the glass film 2, it is preferred that, under a state inwhich the cushion sheet (not shown) is superposed on any one of surfacesof the glass film 2, the glass film 2 and the cushion sheet be woundaround the roll core 3 together. In this case, it is preferred that theroll-to-roll apparatus have both such a configuration as to separate thecushion sheet from the glass film 2 before processing, and such aconfiguration as to superpose the cushion sheet on the glass film 2 andwind the cushion sheet and the glass film again after the processing(for example, see a winding section 19 and an unwinding section 20 forthe resin film 4 illustrated in FIG. 9 described below).

Further, in the above-mentioned embodiment, description is made of thecase where the glass film 2 and the resin film 4 are coupled to eachother by attaching the adhesive tapes 5 across the films. However, theglass film 2 and the resin film 4 maybe coupled to each other by bondingthe films with an adhesive. In this case, it is preferred that, as theadhesive, one that can separate a bonded portion between the glass film2 and the resin film 4 again be used.

Further, the glass film 2 and the resin film 4 may be coupled to eachother by stretching the adhesive tapes 5 across the end portion of theglass film 2 and the end portion of the resin film 4 under a state inwhich both of the end portions are abutted on each other without beingsuperposed on each other or under a state in which both of the endportions are opposed to each other with a gap.

FIG. 3 is a view illustrating a state in which the glass film of theglass roll according to a second embodiment of the present invention isdeveloped on a straight line. The glass roll 1 according to the secondembodiment is different from the glass roll 1 according to the firstembodiment in that the resin films 4 are coupled on both of the leadingend portion and a trailing end portion in the unwinding direction of theglass film 2, respectively.

The roll-to-roll apparatus needs to keep constant tension between theunwinding section 11 and the winding section 12. When the resin film 4is coupled on the trailing end portion in the unwinding direction of theglass film 2, the constant tension can act on the glass film 2 throughthe resin film 4 even after the trailing end portion of the glass film 2is sent out of the unwinding section 11. Therefore, even after thetrailing end portion of the glass film 2 is sent out of the unwindingsection 11, it is possible to perform the predetermined processing, suchas the above-mentioned cleaning, on the glass film 2. As a result, anunprocessed region included in the glass film 2 is reduced, and hence itis possible to achieve effective use of the glass film 2.

Note that, in view of achieving effective use of the glass film 2, it ispreferred that a length D2 of the resin film 4, which corresponds to apart on the rear side of the unwinding direction relative to thetrailing end portion in the unwinding direction of the glass film 2, beequal to or larger than the entire length of the conveyance pathprovided in the inside of the roll-to-roll apparatus. With thisconfiguration, it is possible to stably perform the processing such asthe cleaning up to the trailing end portion in the unwinding directionof the glass film 2, and hence it is possible to more reliably achieveeffective use of the glass film 2. Note that, at this time, it is morepreferred that the length D1 of the resin film 4, which corresponds tothe part on the front side of the unwinding direction relative to theleading end portion in the unwinding direction of the glass film 2, beequal to or larger than the entire length of the conveyance pathprovided in the inside of the roll-to-roll apparatus.

FIGS. 4( a) and 4(b) are views illustrating a coupled portion betweenthe resin film and the glass film of the glass roll according to a thirdembodiment of the present invention. The glass roll 1 according to thethird embodiment is different from the glass roll 1 according to any oneof the first and second embodiments in that the glass film 2 and theresin film 4 are coupled to each other with elastic adhesive tapes 6 aselastic members.

In a case where a widthwise center line L1 of the glass film 2 and awidthwise center line L2 of the resin film 4 are not present on the samestraight line, the roll-to-roll apparatus forcibly corrects displacement(inclination) of the glass film 2, and hence bending stress andtorsional stress act on the portion of the glass film 2 coupled to theresin film 4. Consequently, there may arise a problem in that the glassfilm 2 breaks.

In view of this, as illustrated in FIG. 4( a), the glass film 2 and theresin film 4 are coupled to each other with the elastic adhesive tapes6, and thus the above-mentioned problem is solved. That is, when theglass film 2 and the resin film 4 are coupled to each other with theelastic adhesive tapes 6 as described above, even if the widthwisecenter line L1 of the glass film 2 and the widthwise center line L2 ofthe resin film 4 are not present on the same straight line, asillustrated in FIG. 4( b), the elastic adhesive tapes 6 are deformed atthe point in time when the tension acts on the glass film 2.Consequently, it is possible to absorb the displacement between thewidthwise center line L1 of the glass film 2 and the widthwise centerline L2 of the resin film 4.

Specifically, as illustrated in FIG. 4( a), in a case where, under astate in which the widthwise center line L1 of the glass film 2 isinclined with respect to the widthwise center line L2 of the resin film4, the elastic adhesive tapes 6 are attached on both sides of thewidthwise center line L1 of the glass film 2, as illustrated in FIG. 4(b), the elastic adhesive tape 6 on one side of the widthwise center lineL1 is expanded, and the elastic adhesive tape 6 on the other side of thewidthwise center line L1 is contracted. Owing to the deformation of theelastic adhesive tapes 6, the inclination of the widthwise center lineL1 of the glass film 2 is corrected, and the widthwise center line L1 ofthe glass film 2 and the widthwise center line L2 of the resin film 4substantially conform to each other on the same straight line.Therefore, the bending stress and the torsional stress are less likelyto occur directly on the glass film 2. Thus, even in a case where thewidthwise center line L1 of the glass film 2 and the widthwise centerline L2 of the resin film 4 are not present on the same straight line,it is possible to reliably prevent such a situation that the glass film2 breaks.

Note that, in FIG. 4( a) and FIG. 4( b), description is made of the casewhere the widthwise center line L1 of the glass film 2 and the widthwisecenter line L2 of the resin film 4 intersect each other at an angle.However, even in a case where the center line L1 and the center line L2are parallel to each other, the elastic adhesive tapes 6 are deformedsimilarly, and hence it is possible to absorb the displacement betweenthe center line L1 and the center line L2.

Further, in a case where the resin film 4 is coupled also to thetrailing end portion in the unwinding direction of the glass film 2, itis preferred that the glass film 2 and the resin film 4 be coupled toeach other with the elastic adhesive tapes 6 at both of the leading endportion and the trailing end portion in the unwinding direction of theglass film 2.

Note that, examples of the elastic adhesive tape 6 include a tape thathas a base member formed of a polyester film. Further, the elasticmember that couples the glass film 2 and the resin film 4 to each otheris not limited to the elastic adhesive tape 6, but may be an elasticadhesive.

FIGS. 5( a) and 5(b) are views illustrating a coupled portion betweenthe resin film and the glass film of the glass roll according to afourth embodiment of the present invention. The glass roll 1 accordingto the fourth embodiment is different from the glass roll 1 according tothe third embodiment in that the elastic adhesive tape 6 as the elasticmember couples a region (only one point in the illustrated example)including the widthwise center line L1 of the glass film 2 and thewidthwise center line L2 of the resin film 4.

Specifically, a widthwise center of the elastic adhesive tape 6 conformsto the widthwise center line L1 of the glass film 2 and the widthwisecenter line L2 of the resin film 4. Further, a width of the elasticadhesive tape 6 is smaller than widths of the glass film 2 and the resinfilm, and an intersection between the widthwise center line L1 of theglass film 2 and the widthwise center line L2 of the resin film 4 isincluded in a region where the elastic adhesive tape 6 is attached.

With this configuration, the elastic adhesive tape 6 couples a regionincluding the widthwise center line L1 of the glass film 2 to a regionincluding the widthwise center line L2 of the resin film 4, and hence,even if an area of the coupled portion with the elastic adhesive tape 6is reduced, it is possible to couple the films to each other in stablepostures. Accordingly, owing to a reduction in size of the coupledportion, the stress can be reduced as much as possible, which acts onthe glass film 2 by the elastic adhesive tape 6 absorbs the displacementbetween the widthwise center line L1 of the glass film 2 and thewidthwise center line L2 of the resin film 4. Therefore, this iseffective also in view of preventing breakage of the glass film 2.Further, the elastic adhesive tape 6 is positioned on the widthwisecenter lines of the glass film 2 and the resin film 4, and hence it ispossible to suppress a deformation amount of the elastic adhesive tape6, which is necessary to absorb the displacement between the widthwisecenter line L1 of the glass film 2 and the widthwise center line L2 ofthe resin film 4.

Note that, in FIG. 5( a) and FIG. 5( b), description is made of the casewhere the widthwise center line L1 of the glass film 2 and the widthwisecenter line L2 of the resin film 4 intersect each other at an angle.However, even in a case where the center line L1 and the center line L2are parallel to each other, the elastic adhesive tape 6 is deformedsimilarly, and hence it is possible to absorb the displacement betweenthe center line L1 and the center line L2.

FIGS. 6( a) and 6(b) are views illustrating a state in which the glassfilm of the glass roll according to a fifth embodiment of the presentinvention is developed on a straight line. The glass roll 1 according tothe fifth embodiment is different from the glass roll 1 according to anyone of the first to fourth embodiments in that the glass film 2 issuperposed and attached on one resin film 4 longer in length than theglass film 2, and the resin film 4 is extended beyond at least theleading end portion in the unwinding direction of the glass film 2. Notethat, in the illustrated example, there is illustrated a state in whichthe resin film 4 is extended beyond both of the leading end portion andthe trailing end portion in the unwinding direction of the glass film 2.

With this configuration, while protecting one surface of the glass film2 with the resin film 4, the roll-to-roll apparatus can perform thepredetermined processing on the other surface of the glass film 2.

In this case, it is preferred that the glass film 2 be peelably bondedonto the resin film 4. In this case, the glass film 2 is attached ontothe resin film 4, and hence, even if the glass film 2 breaks, etc., itis possible to prevent such a situation that glass fragments arescattered around. Further, such a situation is less likely to arise thatthe resin film 4 is cut halfway through the roll-to-roll apparatus dueto breakage. Thus, even if such a situation arises that the glass film 2is cut halfway through the roll-to-roll apparatus due to breakage, theconstant tension can act on the glass film 2. Therefore, it is possibleto prevent halfway stop of a roll-to-roll step.

Further, an effective surface of the glass film 2, on which an electrodeor the like is formed, needs to avoid direct contact with another memberas much as possible, and hence it is preferred that the resin film 4 beattached on a surface opposite to the effective surface of the glassfilm 2.

FIG. 7 is a view illustrating a state in which glass films of the glassroll according to a sixth embodiment of the present invention aredeveloped on a straight line. The glass roll 1 according to the sixthembodiment is different from the glass roll 1 according to the fifthembodiment in that a plurality of glass films 2 are attached on oneresin film 4 with longitudinal intervals.

With this configuration, even the plurality of glass films 2 with shortlengths, which are previously cut into fixed lengths, or the pluralityof glass films 2 with short lengths, which are cut due to a defect andthe like at a stage of not having predetermined lengths, can be packagedin a state of the glass roll 1. Further, by being packaged in the stateof the glass roll 1, even the glass films 2 with short lengths can besubjected to the predetermined processing using a roll-to-roll method.

Note that, in this case, sizes (mainly, lengths in a conveyingdirection) of the glass films 2 to be attached on one resin film 4 arenot particularly limited. The glass films 2 may have different sizes.

FIGS. 8( a) and 8(b) are views illustrating a state in which the glassfilm of the glass roll according to a seventh embodiment of the presentinvention is developed on a straight line. The glass roll 1 according tothe seventh embodiment is different from the glass roll 1 according toany one of the fifth and sixth embodiments in that two resin films 4 areattached so as to sandwich entire front and back surfaces of the glassfilm 2 from both sides thereof.

With this configuration, it is possible to protect the entire front andback surfaces of the glass film 2 with the resin films 4. Further, justbefore performing the predetermined processing by the roll-to-rollapparatus, by peeling off the resin film 4 attached on a surface thatneeds to be subjected to the predetermined processing such as thecleaning, it is possible to carry out the predetermined processingwithout any problem.

Specifically, the following can be given as an example of theroll-to-roll apparatus used in this case. In addition to theconfiguration of the roll-to-roll apparatus illustrated in FIG. 2, asillustrated, for example, in FIG. 9, the roll-to-roll apparatusincludes: the winding section 19 for winding the resin film 4 attachedon one surface of the glass film 2 on the upstream side of the cleaningchamber 14, i.e., in a first processing step, to thereby detach theresin film 4 from the one surface of the glass film 2; and the unwindingsection 20 for unwinding the resin film 4 on the downstream side of thestatic elimination chamber 16, i.e., in a final processing step, tothereby attach the resin film 4 on the one surface of the glass film 2again.

Note that, in a case of covering the entire front and back surfaces ofthe glass film 2 with the resin films 4 as described above, it ispreferred that the resin film 4 on the effective surface side of theglass film 2 be not jointed to the glass film 2 through bonding or thelike. This is because, when the resin film 4 is jointed on the effectivesurface side through bonding or the like, there is a fear in thatforeign matters such as bonding components remain on the effectivesurface after the resin film 4 is peeled off from the effective surfaceof the glass film 2. That is, it is preferred that the resin film 4 onthe effective surface side of the glass film 2 be jointed throughbonding or the like only to the resin film 4 opposite to the effectivesurface of the glass film 2.

Further, as illustrated in FIGS. 10( a) and 10(b), entire front and backsurfaces of the plurality of glass films 2 may be covered with two resinfilms 4.

Note that, the present invention is not limited to the above-mentionedembodiments, and can be implemented in various modes. For example, ineach of the above-mentioned embodiments, using the roll-to-rollapparatus illustrated in FIG. 2 or FIG. 9, the glass film 2 is conveyedin a meandering manner by the conveying rollers 13 a to 13 n between theunwinding section 11 and the winding section 12. However, as illustratedin FIG. 11, the glass film 2 may be conveyed along a straight line bythe conveying rollers 13 between the unwinding section 11 and thewinding section 12.

Further, as illustrated in FIG. 12, the glass film 2 may be conveyed inan upright state along a straight line between the unwinding section 11and the winding section 12. When performing the processing using theroll-to-roll method under a state in which the glass film 2 is uprightas described above, in a case of providing the cleaning chamber 14 toperform the cleaning process, there is an advantage that the cleaningliquid is drained satisfactorily. Further, the conveying rollers 13 andthe surface of the glass film 2 are out of direct contact with eachother, and hence it is also possible to reliably prevent such asituation that the surface of the glass film 2 is flawed due to contactwith the conveying rollers 13. Note that, in this case, when the glassfilm 2 flutters, conveying rollers may be added above the glass film 2,and both upper and lower sides of the glass film 2 may be supported bythe conveying rollers.

Further, in the above-mentioned embodiments, description is made of thecase where the glass film 2 is formed by the overflow downdraw method.However, the glass film 2 may be formed by a downdraw method such as aslot downdraw method or a redraw method. When using the downdraw methodin this way, unlike a case of forming the glass film 2 by a floatmethod, the surface of the glass film 2 is not contaminated by tin orthe like. Thus, there is an advantage that the glass film 2 can be usedunder a state in which the surface of the glass film 2 remainsunpolished. The glass roll 1 is targeted for the glass film 2 having asmall thickness, and hence it is also very advantageous to use the glassfilm with a surface remaining unpolished in terms of reducing a risk ofbreakage of the glass film 2. Note that, in view of ensuring smoothnessof the surface of the glass film 2, it is preferred to adopt theoverflow downdraw method or the redraw method among the downdraw method.

INDUSTRIAL APPLICABILITY

The present invention can be preferably used to a glass substrate usedfor a flat panel display, such as a liquid crystal display or an OLEDdisplay, and for a device such as a solar cell, and used to cover glassfor an OLED lighting.

REFERENCE SIGNS LIST

1 glass roll

2 glass film

3 roll core

4 resin film

5 adhesive tape

6 elastic adhesive tape (elastic member)

11 unwinding section

12 winding section

14 cleaning chamber

15 drying chamber

16 static elimination chamber

1. A glass roll, which is formed by winding a glass film into a roll,wherein a resin film is attached onto the glass film, and at least apart of the resin film is arranged on a front side of an unwindingdirection relative to a leading end portion in the unwinding directionof the glass film.
 2. The glass roll according to claim 1, wherein theresin film is coupled to the leading end portion in the unwindingdirection of the glass film.
 3. The glass roll according to claim 2,wherein the resin film is coupled also to a trailing end portion in theunwinding direction of the glass film, and wherein at least a part ofthe resin film is arranged on a rear side of the unwinding directionrelative to the trailing end portion in the unwinding direction of theglass film.
 4. The glass roll according to claim 2, wherein the glassfilm and the resin film are coupled to each other with an elasticmember.
 5. The glass roll according to claim 4, wherein the elasticmember couples a region including a widthwise center line of the glassfilm and a widthwise center line of the resin film.
 6. The glass rollaccording to claim 2, wherein the glass film and the resin film arecoupled to each other under a state in which an end portion of the resinfilm is superposed on an end portion of the glass film.
 7. The glassroll according to claim 1, wherein the resin film longer in length thanthe glass film is superposed and attached onto one surface of the glassfilm, and the resin film is extended beyond the leading end portion inthe unwinding direction of the glass film.
 8. The glass roll accordingto claim 7, wherein the resin film is extended also beyond a trailingend portion side in the unwinding direction of the glass film.
 9. Theglass roll according to claim 7, wherein the glass film comprises aplurality of glass films, and wherein the plurality of glass films areattached onto the same resin film.
 10. The glass roll according to claim7, wherein the resin film is superposed and attached onto the onesurface of the glass film, and an another resin film separate from theresin film is superposed and attached onto another surface of the glassfilm.
 11. A processing method for a glass roll, for sequentiallyperforming, by a roll-to-roll apparatus, predetermined processing on aglass roll including a glass film wound into a roll, the processingmethod comprising: attaching a resin film onto the glass film; arrangingat least a part of the resin film on a front side of an unwindingdirection relative to a leading end portion in the unwinding directionof the glass film; and guiding the glass film into the roll-to-rollapparatus while the resin film is in the lead.
 12. The processing methodfor a glass roll according to claim 11, wherein a length of the resinfilm, which corresponds to a part on the front side of the unwindingdirection relative to the leading end portion in the unwinding directionof the glass film, is equal to or larger than an entire length of aconveyance path for the glass film in the roll-to-roll apparatus. 13.The processing method for a glass roll according to claim 11, wherein atleast a part of the resin film is arranged also on a rear side of theunwinding direction relative to a trailing end portion in the unwindingdirection of the glass film.
 14. The processing method for a glass rollaccording to claim 13, wherein a length of the resin film, whichcorresponds to a part on the rear side of the unwinding directionrelative to the trailing end portion in the unwinding direction of theglass film, is equal to or larger than the entire length of theconveyance path for the glass film in the roll-to-roll apparatus. 15.The glass roll according to claim 3, wherein the glass film and theresin film are coupled to each other with an elastic member.
 16. Theglass roll according to claim 15, wherein the elastic member couples aregion including a widthwise center line of the glass film and awidthwise center line of the resin film.
 17. The glass roll according toclaim 3, wherein the glass film and the resin film are coupled to eachother under a state in which an end portion of the resin film issuperposed on an end portion of the glass film.
 18. The glass rollaccording to claim 4, wherein the glass film and the resin film arecoupled to each other under a state in which an end portion of the resinfilm is superposed on an end portion of the glass film.
 19. The glassroll according to claim 5, wherein the glass film and the resin film arecoupled to each other under a state in which an end portion of the resinfilm is superposed on an end portion of the glass film.
 20. The glassroll according to claim 15, wherein the glass film and the resin filmare coupled to each other under a state in which an end portion of theresin film is superposed on an end portion of the glass film.